The movie has a vague, semi-buried message about helping people, even if one doesn't have great means. But mostly this is a story about being in the right place at the right time.
Some Hell's Angels beat up some debt collectors in one scene. A band crashes a big truck on the freeway. There's a fight in a convenience store with stabbing and blood (one band member is sent to the hospital). The lead singer of the Dead Boys pretends to choke himself with the microphone cord (and seems to be actually doing it). A dead body shows up in front of the door to the club. The music sometimes has violent themes. Finally, in a prologue, a baby escapes from its crib and runs out the front door and into the woods; the sequence can be harrowing for parents, but the baby comes out fine.
One female breast is shown, and a few male butts. Minor characters are shown making out and participating in oral sex in the club's bathroom. These scenes are shown very quickly in fast-motion montages. A musician makes a reference to masturbating.
Language is strong, but without much variety. It includes multiple uses of "f--k," "s--t," "motherf--ker," "p---y," "c--k," and "ass."
The main character likes to drink Fresca and references it at least twice.
The movie takes place at a nightclub/bar, and the liquor flows freely throughout. Characters also smoke cigarettes throughout. One supporting character is shown to be a junkie, though he's never seen taking drugs. (He just appears sleepy and confused.) Minor characters are shown snorting cocaine. The main character swigs from a bottle of vodka, and then pours it in the gas tank of his truck.